Abstract
	By this paper, we rapport scientific results concerning the Ti based alloy Ti -10Mo - 8V - 1Fe - 3,5Al, used mainly for aerospace industry. We have established some correlations between hardness – structural transformations – heat treatment variants – technological parameters. First, we present some theoretical considerations about equilibrium phase status as a result of discussions on equilibrium ternary diagrams, about melting temperature of the alloy, and about the determination procedure of the stabilisation coefficient of the ? phase (k?).  We have determined, applying an analytical method, the transition temperature of the ? ? ? ? ? transformation. We have applied some heat treatments, which variants were the following: 
1. cold rolling and annealing at different temperatures (400?C, 450?C, 500?C, 550?C, 600?C) and different maintaining times (0.18h; 1h; 2h; 4h; 8h; 16h; 32h; 64h);
2. hardening from 800?C  for dissolving in solution, and ageing at same temperatures and 
durations like precedent annealing variant;
3. hardening from 900?C  for dissolving in solution, and ageing in same conditions like variant no. 2.
	After heat treatments we have determined hardness HV and established corresponding HV curves as a function of annealing or ageing temperatures and maintaining times. As a result of a statistical processing of the experimental data, using MATCAD program, we have obtained the equations of linear correlation and linear regression for HV = f (time) Temp = const. We have obtained also the HV iso-hardness curves for each type of applied heat treatment.